Pdcch Ordered Random Access Channel Procedure for Reduced Capability User Equipment

1. A user equipment, comprising: one or more memories comprising computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the user equipment to: transmit an indication of one or more capabilities of the user equipment; receive a physical downlink control channel (PDCCH) that orders the user equipment to perform a random access channel (RACH) procedure on an uplink carrier based on the one or more capabilities of the user equipment; and perform the RACH procedure on the uplink carrier when a gap between a last symbol of the PDCCH and a first symbol of a RACH message is equal to or larger than a minimum gap that is based on a half-duplex switching delay.

2. The user equipment of claim 1, the one or more processors further cause the user equipment to determine the minimum gap prior to performing the RACH procedure, wherein the minimum gap includes the half-duplex switching delay.

3. The user equipment of claim 1, wherein the minimum gap is based on at least one of: a UE processing capability for reference signal received power (RSRP) measurement, the PDCCH, a physical RACH (PRACH), or a physical uplink shared channel (PUSCH); a minimum subcarrier spacing (SCS) configuration of the PDCCH, the PRACH, or the PUSCH; a bandwidth part (BWP) switching delay; a delay extension based on an operating frequency range (FR); a switching gap between downlink reception and uplink transmission; or a combination thereof.

4. The user equipment of claim 3, wherein the minimum gap is based on the UE processing capability for RSRP measurement, the PDCCH, the PRACH, or the PUSCH.

5. The user equipment of claim 3, wherein the minimum gap is based on the minimum SCS configuration of the PDCCH, the PRACH, or the PUSCH.

6. The user equipment of claim 3, wherein the minimum gap is based on the BWP switching delay.

7. The user equipment of claim 3, wherein the minimum gap is based on the delay extension based on the operating FR.

8. The user equipment of claim 3, wherein the minimum gap is based on the switching gap between downlink reception and uplink transmission.

9. The user equipment of claim 3, wherein: the BWP switching delay depends on the one or more capabilities of the user equipment; and the switching gap depends on the one or more capabilities of the user equipment.

10. The user equipment of claim 1, wherein the PDCCH indicates the uplink carrier, and wherein the uplink carrier is a normal uplink carrier or a supplementary uplink (SUL) carrier within an uplink bandwidth part (BWP) smaller than or equal to a maximum uplink BWP capability of the user equipment.

11. The user equipment of claim 1, wherein a type of the RACH procedure comprises: a first type of RACH procedure in which the user equipment transmits a first type of RACH message that includes a physical RACH (PRACH) preamble; or a second type of RACH procedure in which the user equipment transmits a second type of RACH message that includes a composite of the PRACH preamble and a physical uplink shared channel (PUSCH).

12. The user equipment of claim 11, wherein: the RACH procedure is performed with coverage enhancement (CE) based on the one or more capabilities of the user equipment; and the CE comprises at least one of: repetition of the PRACH preamble; repetition of the PUSCH; frequency hopping for the PRACH preamble; frequency hopping for the PUSCH; or demodulation reference signal (DMRS) bundling for the PUSCH.

13. The user equipment of claim 11, wherein the PDCCH indicates the type of the RACH procedure and a synchronization signal block (SSB) index, wherein an uplink bandwidth part (BWP) for the RACH procedure is associated with a downlink BWP containing the SSB, and wherein the SSB comprises a cell-defining SSB (CD-SSB) or a non-cell-defining SSB (NCD-SSB).

14. The user equipment of claim 12, wherein the PDCCH indicates the type of the RACH procedure via bits in at least one of: a frequency domain resource allocation (FDRA) field, a DMRS configuration of the PDCCH; an index of the PRACH preamble; an index of a PRACH preamble group; or an index of a PRACH mask.

15. The user equipment of claim 1, wherein the minimum gap is based on at least one of: an uplink switching gap that depends on the one or more capabilities of the user equipment; an uplink transmission switching option; a quasi co-location (QCL); a transmission configuration indicator (TCI) state; a synchronization signal block (SSB); or a downlink reference signal configuration of a serving cell.

16. The user equipment of claim 1, wherein the indication of the one or more capabilities of the user equipment comprises at least one of: an indication that the user equipment is a reduced capability (RedCap) user equipment; or an indication of a capability of the user equipment to support half-duplex.

17. The user equipment of claim 1, wherein the one or more capabilities of the user equipment comprise at least one of: a capability of the user equipment to support a type of RACH procedure; a capability of the user equipment to support coverage enhancement (CE); a capability of the user equipment to support half-duplex frequency division duplexing (FDD); a radio frequency (RF) retuning capability of the user equipment; or a capability of the user equipment for processing the PDCCH, a physical RACH (PRACH), or a physical uplink shared channel (PUSCH).

18. The user equipment of claim 1, wherein the minimum gap is based on at least one of: a type of the RACH procedure; or a coverage enhancement (CE) of the RACH procedure.

19. The user equipment of claim 1, wherein the PDCCH indicates one or more power control parameters for a physical RACH (PRACH) message based on the one or more capabilities of the user equipment.

20. The user equipment of claim 19, wherein the one or more power control parameters depend on at least one of: a type of the RACH procedure; a power control scheme; a transmission configuration indicator (TCI) state; a quasi co-location (QCL) state; or a contention resolution scheme for the RACH procedure.

21. The user equipment of claim 20, wherein the one or more power control parameters comprise at least one of: an indicator of an uplink full power transmission parameter; a TCI state; a QCL state; a transmission power control (TPC) command; a transmit power ramp-up parameter; or a transmit power offset between a physical RACH (PRACH) and physical uplink shared channel (PUSCH) transmission.

22. The user equipment of claim 1, wherein: the PDCCH comprises a groupcast PDCCH transmitted in a common search space (CSS) set; and a payload or cyclic redundancy check (CRC) bits of the payload is scrambled by a group radio network temporary identifier (RNTI).

23. The user equipment of claim 1, wherein the half-duplex switching delay comprises a first delay for the user equipment to switch from uplink transmission to downlink reception or a second delay for the user equipment to switch from downlink reception to uplink transmission.

24. A method of wireless communication by a user equipment, the method comprising: transmitting an indication of one or more capabilities of the user equipment; receiving a physical downlink control channel (PDCCH) that orders the user equipment to perform a random access channel (RACH) procedure on an uplink carrier based on the one or more capabilities of the user equipment; and performing the RACH procedure on the uplink carrier when a gap between a last symbol of the PDCCH and a first symbol of a RACH message is equal to or larger than a minimum gap that is based on a half-duplex switching delay.

25. The method of claim 24, further comprising determining the minimum gap prior to performing the RACH procedure, wherein the minimum gap includes the half-duplex switching delay.

26. The method of claim 24, wherein the minimum gap is based on at least one of: a UE processing capability for reference signal received power (RSRP) measurement, the PDCCH, a physical RACH (PRACH), or a physical uplink shared channel (PUSCH); a minimum subcarrier spacing (SCS) configuration of the PDCCH, the PRACH, or the PUSCH; a bandwidth part (BWP) switching delay; a delay extension based on an operating frequency range (FR); a switching gap between downlink reception and uplink transmission; or a combination thereof.

27. The method of claim 26, wherein the minimum gap is based on the UE processing capability for RSRP measurement, the PDCCH, the PRACH, or the PUSCH.

28. The method of claim 26, wherein the minimum gap is based on the minimum SCS configuration of the PDCCH, the PRACH, or the PUSCH.

29. The method of claim 26, wherein the minimum gap is based on the BWP switching delay.

30. A network entity, comprising: one or more memories comprising computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the network entity to: obtain an indication of one or more capabilities of a user equipment; outputting for transmission, to the user equipment, a physical downlink control channel (PDCCH) that orders the user equipment to perform a random access channel (RACH) procedure based on one or more capabilities of the user equipment; and obtain a RACH message from the user equipment after a minimum gap between a last symbol of the PDCCH and a first symbol of the RACH message, wherein the minimum gap is based on a half-duplex switching delay.